This invention relates to a circuit arrangement in which a resistor is constituted by a layer of electrically resistive material supported by an insulating substrate. In order to produce such a resistor having a fairly high resistance value it is usual either to make the resistive layer long in relation to its cross-sectional area, or to make the resistive layer very thin. Both of these expedients have attendant disadvantages. For example, a very long narrow resistor may be wasteful of the available area of the insulating substrate, and if it is too thin imperfections in the layer or the surface of the insulating substrate may result in open circuits. Also, it is difficult to reliably manufacture resistors having precisely specified values from a layer of resistive material which is very thin, i.e. of the order of a few hundred Angstroms or less, as the electrical properties of the layer, such as resistance and temperature coefficient of resistance for example, may become unstable or unpredictable as the thickness becomes less.
The present invention seeks to provide an improved circuit arrangement in which the above-mentioned disadvantages can be reduced.